State highway officials contacted the Rev. Spencer E. Jackson a few weeks ago with astonishing news: They had found the remnants of a homestead that belonged to his great-great-grandmother, a freed slave.

Less than two miles from his church was a remarkably preserved site, full of artifacts that provide clues to 19th-century black life. Eyeglasses, fragments of dolls and an 1860 Abraham Lincoln campaign medallion are among the discoveries that help tell the story of Melinda Jackson, who bought the property in 1869.

Yesterday, Mr. Jackson and other relatives came to the wooded area tucked between a car dealership and busy Route 29 in Silver Spring for a last look at the site before archeologists finish their dig and the area gets paved over. The Intercounty Connector, a long-planned highway through central Montgomery and northern Prince George’s counties, will cut through the grove of tall tulip poplars, leaving no trace of the former homestead.

Mr. Jackson, pastor of Abyssinia Baptist Church in Silver Spring, said he knew his family had owned property in the area, but never knew its exact location.

“We’re so blessed by God Almighty. I mean we’re only a few hundred feet from Route 29, the autopark is right on the edge. And no one decided to develop this area,” he said. “We so appreciate that somebody had a watchful eye as they were going through construction.”

The discovery was no accident, however. Federal and state regulations require surveys of land where highways are being built to protect just this sort of site from being paved over before first being thoroughly searched for objects of historical value.

Still, it’s rare to come across a site that is so well-preserved, untouched by bulldozers, said Julie Schablitsky, chief of cultural resources at the Maryland State Highway Administration.

The Jackson house was destroyed by fire about 1917. Fire, said Miss Schablitsky, is an archaeologist’s best friend. Unlike homes that have been abandoned, those destroyed by fire contain objects that were actually in use, rather than just trash.

Archaeologists first found the site in 2003 and conducted an initial survey the following year. They realized they needed to keep digging.

More intensive work started in January. That’s when archaeologists found the first evidence that people of African descent had lived there. A quartz crystal the size of a large egg was found buried under the house.

“Crystals …are almost a calling card of people of African descent living here,” Miss Schablitsky said. “Crystals to them, if they buried [them] next to a foundation or under the floorboards, it was a way of protecting the home.”

Other artifacts provide a window onto everyday life in the house. There are fragments of a black baby doll made of painted porcelain. The fragments show the doll’s painted-on eyebrows and pierced ears.

An 1860 campaign medallion reads, “Abraham Lincoln. Free soil, free men.” It featured photographs of Lincoln and his first vice president, Hannibal Hamlin, though they are no longer visible.

Mr. Jackson took the medallion as evidence that the family was “aware of the political situation in America,” he said. “This is not somebody living back in the woods without really knowing what was going on.”

The artifacts will be housed at the Jefferson Patterson Park and Museum, a state archaeology museum in St. Leonard.

It was detective work by Mechelle L. Kerns-Nocerito, an archaeologist with URS Corp., the company that conducted the dig for the highway administration, that led the team to the name Melinda Jackson. Mrs. Kerns-Nocerito compared a map from that time with census records. She learned that Melinda Jackson most likely was born into slavery. She may have been owned by Ann M. Downs, the woman who sold her 83/4 acres in 1869.

It is not clear when the house was built on the property, but Mrs. Kerns-Nocerito said it’s possible it was already there when Jackson purchased the land and had previously served as quarters for Downs’ slaves.

“She may have sold her the part of the property that the family had already lived on. That in my mind faces the most logic,” Mrs. Kerns-Nocerito said.

Archaeologists don’t think anyone was killed in the fire that destroyed the home. The family moved to a place nearby and sold the property. Eventually, it was acquired by a gravel- and sand-mining company, which, as luck would have it, never used it.

After learning who had owned the land, Mrs. Kerns-Nocerito tracked down Jackson’s living descendants, many of whom still reside in the area.

Among them is Bernadette Lee King, 61, of Gaithersburg, who found out about the site only last week from other members of the extended family. She said the thrill of the discovery was bittersweet, since it will soon be just a road.

Her husband, Elwood King, added: “The sad thing is it’s been here all this time, but nobody ever kept the property in the family.”

Before leaving, the couple took some rocks from the foundation to put on their mantle.